Space exploration and the military require robots that are mobile, maneuverable, and can perform a large number of different tasks while taking up minimum space and weight during transport. Reconfigurable modular robotic systems have been of keen interest due to their improved ability to overcome obstacles and perform more tasks using a single hardware platform.
Toward this goal, researchers have investigated homogenous robotic modules for reconfigurable manipulation, mobility, or combinations therein. Homogeneity can reduce maintenance, offer increase robustness through redundancy, provide compact and ordered storage, and increase adaptability. Modularity can suit the system to compact and ordered storage, which can be critical for military and space deployment.
The use of compliant frame modules can further increase a modular robot's usefulness. Compliant frames allow a robotic system to change its shape by deflecting the frame module to achieve a near infinite number of different steering and maneuverability strategies. Likewise, the compliant frame modules allow the axles to deflect in order to accommodate terrain variations.
A robotic modular wheeled robot with a compliant frame may be reconfigured to perform tasks such as reconnaissance, transporting of goods, and search and rescue. Using the compliant frame, the robot can overcome unexpected terrain challenges and accomplish its mission. Such a robot may be used on an extraterrestrial mission to Mars or one of Jupiter's moons, where modularity would allow the robot to replace modules that cease to function properly.
Although the flexibility of the compliant frame system can enhance the capability of the robot, it provides a significant additional complexity in the control of the robot. Previous control functions derived for rigid robotic systems can fail to properly control modular robotic systems with compliant frames.
An additional challenge is presented in controlling a reconfigurable modular robot. As the configuration of the robot is changed, different ways in which the robot may move are provided. Control functions must be adapted whenever the configuration of the robotic system is changed, adding an additional level of difficulty.